Intelligent boom control hydraulic system

Abstract

An intelligent knuckle boom control system is disclosed where hoist and stick cylinders raise and lower main and stick booms, respectively, a base end control valve controls flow to the hoist and stick cylinder base ends, a hoist rod control valve controls flow to the hoist cylinder rod end, and a stick rod control valve controls flow to the stick cylinder rod end. A microprocessor computes control signals to direct flow through the control valves based on operator commands and boom position readings. The system can include an energy storage system for storing excess energy and releasing the stored energy, where the microprocessor directs storage of excess energy and release of stored energy. The energy storage system can include a hydraulic accumulator, an accumulator control valve and hydraulic pressure sensors; where the microprocessor receives pressure sensor readings and computes accumulator control valve control signals.

We claim: 
     
       1. An intelligent boom control hydraulic system for a knuckle boom system including a main boom and a stick boom coupled at a knuckle; the intelligent boom control hydraulic system comprising:
 a hoist hydraulic cylinder for raising and lowering the main boom, the hoist hydraulic cylinder having a rod end and a base end; 
 a stick hydraulic cylinder for raising and lowering the stick boom, the stick hydraulic cylinder having a rod end and a base end; 
 a hoist boom position sensor providing hoist boom position readings; 
 a stick boom position sensor providing stick boom position readings; 
 a hydraulic fluid pump; 
 a hydraulic reservoir including hydraulic fluid; 
 a base end control valve controlling flow from the hydraulic fluid pump to the base ends of the hoist and stick hydraulic cylinders, and controlling flow from the base ends of the hoist and stick hydraulic cylinders to the hydraulic reservoir; 
 a hoist rod control valve controlling flow from the hydraulic fluid pump to the rod end of the hoist hydraulic cylinder, and controlling flow from the rod end of the hoist hydraulic cylinder to the hydraulic reservoir; 
 a stick rod control valve controlling flow from the hydraulic fluid pump to the rod end of the stick hydraulic cylinder, and controlling flow from the rod end of the stick hydraulic cylinder to the hydraulic reservoir; 
 an operator input device for input of operator commands; and 
 a microprocessor computing control signals to direct flow through the base end control valve, the hoist rod control valve and the stick rod control valve based on the operator commands and the hoist and stick boom position readings. 
 
     
     
       2. The intelligent boom control hydraulic system of  claim 1 , wherein during operation at least two of the base end control valve, the hoist rod control valve and the stick rod control valve are activated, one of the activated valves coupling the stick or hoist hydraulic cylinder to the hydraulic fluid pump and the other of the activated valves coupling the stick or hoist hydraulic cylinder to the hydraulic reservoir. 
     
     
       3. The intelligent boom control hydraulic system of  claim 1 , further comprising a hoist counter-balance valve controlling flow between the base end control valve and the base end of the hoist hydraulic cylinder. 
     
     
       4. The intelligent boom control hydraulic system of  claim 1 , further comprising a stick counter-balance valve controlling flow between the base end control valve and the base end of the stick hydraulic cylinder. 
     
     
       5. The intelligent boom control hydraulic system of  claim 1 , wherein the hoist boom position sensor is a hoist cylinder position sensor determining the length of the hoist hydraulic cylinder. 
     
     
       6. The intelligent boom control hydraulic system of  claim 5 , wherein the stick boom position sensor is a stick cylinder position sensor determining the length of the stick hydraulic cylinder. 
     
     
       7. The intelligent boom control hydraulic system of  claim 1 , further comprising a hoist counter-balance valve controlling flow between the base end control valve and the base end of the hoist hydraulic cylinder, and a stick counter-balance valve controlling flow between the base end control valve and the base end of the stick hydraulic cylinder. 
     
     
       8. The intelligent boom control hydraulic system of  claim 7 , wherein when retracting the hoist cylinder and extending the stick cylinder simultaneously, the hoist rod control valve couples the hydraulic fluid pump to the rod end of the hoist cylinder activating the hoist counter balance valve and allowing hydraulic fluid to flow from the base end of the hoist cylinder to the base end of the stick cylinder extending the stick cylinder and pushing hydraulic fluid from the rod end of the stick cylinder through the stick rod control valve to the hydraulic reservoir. 
     
     
       9. The intelligent boom control hydraulic system of  claim 7 , wherein when retracting the stick cylinder and simultaneously extending the hoist cylinder, the stick rod control valve couples the hydraulic fluid pump to the rod end of the stick cylinder activating the stick counterbalance valve and allowing hydraulic fluid to flow from the base end of the stick cylinder to the base end of the hoist cylinder extending the hoist cylinder and pushing hydraulic fluid from the rod end of the hoist cylinder through the hoist rod control valve to the hydraulic reservoir. 
     
     
       10. The intelligent boom control hydraulic system of  claim 1 , further comprising an energy storage system for storing excess energy and releasing the stored energy; the microprocessor computing control signals to direct storage of excess energy and release of stored energy. 
     
     
       11. The intelligent boom control hydraulic system of  claim 10 , wherein the energy storage system comprises a hydraulic accumulator, an accumulator control valve and a plurality of hydraulic pressure sensors; the microprocessor receiving readings from the plurality of hydraulic pressure sensors and computing control signals for the accumulator control valve. 
     
     
       12. The intelligent boom control hydraulic system of  claim 11 , wherein when operation of the intelligent boom control hydraulic system results in excess energy, the excess energy is routed through the accumulator control valve and stored in the hydraulic accumulator; and
 wherein when the hydraulic accumulator has stored energy and operation of the intelligent boom control hydraulic system needs additional energy, the stored energy from the hydraulic accumulator is routed through the accumulator control valve to the hoist and stick cylinders. 
 
     
     
       13. The intelligent boom control hydraulic system of  claim 12 , wherein when the hydraulic accumulator has stored energy and operation of the intelligent boom control hydraulic system needs additional energy, the stored energy from the hydraulic accumulator is routed through the accumulator control valve to the base end of the hoist cylinder and the base end of the stick cylinder. 
     
     
       14. The intelligent boom control hydraulic system of  claim 11 , further comprising a one-way valve coupling the hydraulic fluid pump to the hydraulic accumulator through the hydraulic control valve, the one-way control valve allowing fluid to flow from the hydraulic fluid pump to the hydraulic control valve for energy storage in the hydraulic accumulator. 
     
     
       15. The intelligent boom control hydraulic system of  claim 11 , wherein the plurality of hydraulic pressure sensors comprises a pump line pressure sensor, a reservoir line pressure sensor, a work line pressure sensor and an accumulator pressure sensor. 
     
     
       16. The intelligent boom control hydraulic system of  claim 11 , further comprising a hoist counter-balance valve controlling flow between the base end control valve and the base end of the hoist hydraulic cylinder, and a stick counter-balance valve controlling flow between the base end control valve and the base end of the stick hydraulic cylinder. 
     
     
       17. The intelligent boom control hydraulic system of  claim 16 , wherein the accumulator control valve is coupled between the base end control valve and the hoist and stick counter-balance valves. 
     
     
       18. The intelligent boom control hydraulic system of  claim 17 , further comprising a one-way valve coupling the hydraulic fluid pump to the hydraulic accumulator through the accumulator control valve, the one-way control valve allowing fluid to flow from the hydraulic fluid pump to the accumulator control valve for energy storage in the hydraulic accumulator. 
     
     
       19. The intelligent boom control hydraulic system of  claim 18 , wherein energy can be transferred between the base end of the hoist hydraulic cylinder and the base end of the stick hydraulic cylinder through the hoist counter-balance valve and the stick counter-balance valve. 
     
     
       20. The intelligent boom control hydraulic system of  claim 19 , wherein energy can be transferred between the hoist and stick hydraulic cylinders and the hydraulic accumulator through the accumulator control valve.